1. Suggested changes to the English names of some Western Palearctic birds;Atkin;The Ibis,1988
2. BBRC 2017 https://www.bbrc.org.uk/main-information/statistics
3. Records Committee: Sixth Report (February 1971);BOU;The Ibis,1971
4. British Ornithologists’ Union Records Committee 13th Report (December 1987);BOU;The Ibis,1988